MediaWiki:AjaxSubmit.js

// ajaxSubmit
//   Submit a form through Ajax. Doesn't handle file uploads yet.
//
// Parameters:
//   form                 DOM element   The form to submit
//   button      optional DOM element   If set and a submit button of 'form', is added to the
//                                      form arguments sent
//   func        optional Function      Function to call once the call has been made or the
//                                      result has arrived, if want_result == true
//   want_result optional Boolean       If true, call func with the result of the submit once
//                                      it has arrived. Otherwise, call func as soon as the
//                                      submit request has been received by the server, and
//                                      ignore any result of the submit.
//
// Notes:
//   Func should be a function (request). If func is not defined,
//   ajaxSubmit just submits the form and ignores any result.
function ajaxSubmit( form, button, func, want_result ) {
	if ( want_result && ( !func || typeof( func ) != 'function' || func.length < 1 ) ) {
		/**** TODO: improve error handling: should throw an exception! */
		alert( 'Logic error in ajaxSubmit: func must be function (request).' );
		return;
	}
	if ( func && typeof( func ) != 'function' ) {
		/**** TODO: improve error handling: should throw an exception! */
		alert( 'Error in ajaxSubmit: func must be a function, found a ' + typeof( func ) + '.' );
		return;
	}

	var is_simple = false;
	// True if it's a GET request, or if the form is 'application/x-www-form-urlencoded'
	var boundary = null;
	// Otherwise, it's 'multipart/form-data', and the multipart delimiter is 'boundary'

	function encode_entry( name, value ) {
		if ( !name || name.length == 0 || !value || value.length == 0 ) {
			return null;
		}
		if ( !boundary ) {
			return name + '=' + encodeURIComponent( value );
		} else {
			return boundary + '\r\n'
				+ 'Content-Disposition: form-data; name="' + name + '"\r\n'
				+ '\r\n'
				+ value + '\r\n'; // Must be encoded?? How? escape? or encodeURIComponent?
		}
	}

	function encode_field( element ) {
		var name = element.name;
		if ( !name || name.length == 0 ) {
			name = element.id;
		}
		return encode_entry( name, element.value );
	}

	function form_add_argument( args, field ) {
		if ( !field || field.length == 0 ) {
			return args;
		}
		if ( !args || args.length == 0 ) {
			return field;
		}
		if ( is_simple ) {
			return args + '&' + field;
		} else {
			return args + field;
		}
	}

	var request;
	if ( window.LAPI && window.LAPI.Ajax && window.LAPI.Ajax.getRequest ) {
		request = window.LAPI.Ajax.getRequest();
	} else {
		try {
			request = new window.XMLHttpRequest();
		} catch ( anything ) {
			if ( window.ActiveXObject ) {
				request = new window.ActiveXObject( 'Microsoft.XMLHTTP' );
			}
		}
	}

	var method = form.getAttribute( 'method' ).toUpperCase();
	var uri = form.getAttribute( 'action' );
	if ( uri.length >= 2 && uri.substring( 0, 2 ) == '//') {
		// Protocol-relative URI; can cause trouble on IE7
		uri = document.location.protocol + uri;
	} else if ( uri.charAt( 0 ) == '/' ) {
		// Some browsers already expand the action URI (e.g. Opera 9.26)
		uri = mw.config.get('wgServer') + uri;
		if ( uri.length >= 2 && uri.substring( 0, 2 ) == '//' ) {
			uri = document.location.protocol + uri;
		}
	}
	// Encode the field values

	var is_get = method == 'GET';
	var encoding = form.getAttribute( 'enctype' );
	if ( encoding != null ) {
		encoding = encoding.toLowerCase ();
		if (encoding.length == 0) encoding = null;
	}
	is_simple =
		is_get || encoding == null || encoding == 'application/x-www-form-urlencoded';

	var args = '';
	var boundary_string = '----' + wgArticleId + wgCurRevisionId + 'auto_submit_by_lupo';

	boundary = null;

	if ( !is_simple ) {
		boundary = '--' + boundary_string;
	}

	for ( var i = 0; i < form.elements.length; i++ ) {
		var element = form.elements[i];
		var single_select = false;
		switch ( element.type ) {
			case 'checkbox':
			case 'radio':
				if (!element.checked) break;
				// else fall-through
			case 'hidden':
			case 'text':
			case 'password':
			case 'textarea':
				args = form_add_argument( args, encode_field( element ) );
				break;
			case 'select-one':
				single_select = true;
				// fall-through
			case 'select-multiple':
				var name = element.name || element.id || '';
				if ( name.length == 0 ) {
					break;
				}
				for ( var j = 0; j < element.length; j++ ) {
					if ( element[j].selected ) {
						var value = element[j].value || element[j].text;
						args = form_add_argument( args, encode_entry( name, value ) );
						if ( single_select ) {
							break; // No need to scan the rest
						}
					}
				}
				break;
			case 'file':
				break;
		}
	}

	if ( button && button.form == form && button.type == 'submit' ) {
		args = form_add_argument( args, encode_field( button ) );
	}

	// Close the multipart request
	if ( !is_simple && args.length > 0 ) {
		args = args + boundary;
	}

	if ( method == 'GET' ) {
		uri = uri + ( uri.indexOf( '?' ) < 0 ? '?' : '&' ) + args;
		args = null;
	}

	// Make the request
	request.open( method, uri, true );
	if ( want_result && request.overrideMimeType ) {
		request.overrideMimeType( 'application/xml' );
	}
	request.setRequestHeader( 'Pragma', 'cache=no' );
	request.setRequestHeader( 'Cache-Control', 'no-transform' );
	if ( method == 'POST' ) {
		if ( encoding == null ) {
			encoding = 'application/x-www-form-urlencoded';
		}
		if ( !is_simple ) {
			request.setRequestHeader(
				'Content-type', encoding + '; charset=UTF-8; boundary="' +
					boundary_string + '"'
			);
		} else {
			request.setRequestHeader( 'Content-type', encoding );
		}
		try {
			request.setRequestHeader( 'Content-length', args.length );
		} catch ( anything ) {
			// Just swallow. Some browsers don't like setting this but prefer to do it themselves.
			// Safari 4 for instance issues an "error" about an "unsafe" setting not done, but then
			// continues anyway. The exception handler here is just paranoia in case someone decides
			// to make this a hard error.
		}
	}

	request.onreadystatechange = function() {
		if ( want_result ) {
			if ( request.readyState < 4 ) {
				return;
			}
			func( request );
		} else {
			// Call func as soon as the request has been sent and we start getting the result.
			if ( request.readyState == 3 && func ) {
				func( request );
			}
		}
	}

	request.send( args );
}

// submitAndClose
//   Submit a form and close the window containing it as soon as the request has been
//   received by the server
//
// Parameters:
//   form   DOM element   The form to submit.
function submitAndClose( form ) {
	ajaxSubmit( form, null, function() { window.close(); } );
}